The pressure at which typical fluid distribution systems supply fluid may vary according to the demands placed on the system, the climate, the source of supply, and/or other factors. However, most end-user facilities equipped with gas appliances such as furnaces, ovens, etc., require the gas to be delivered in accordance with a predetermined pressure, and at or below a maximum capacity of a gas regulator. Therefore, fluid regulators are implemented in these distribution systems in order to ensure that the delivered gas meets the requirements of the end-user facilities.
Direct-operated fluid regulators are primarily designed for industrial and commercial applications supplying fluids, such as natural gas and propane, to furnaces, burners, and other appliances and are generally well known in the art. Fluid regulators are typically used to regulate the pressure of a fluid to a substantially constant value. Specifically, a fluid regulator has an inlet that typically receives a supply fluid at a relatively high pressure and provides a relatively lower and substantially constant pressure at an outlet. To regulate the downstream pressure, fluid regulators commonly include a sensing element or diaphragm to sense an outlet pressure in fluid communication with a downstream pressure. Fluid regulators can also include balancing systems that can be used to counteract the force applied to the top of a valve disk by the higher pressure inlet fluid and possible also the force applied to a bottom of the valve disk by exhaust fluid that passes around the valve disk.